The BBC reports that this is the strongest quake to hit the country since 1976.

The BBC adds:

"President Otto Perez Molina told the BBC that 22 people were still missing and as many as 10,000 houses may have been rendered uninhabitable.

"Most of the damage was in San Marcos region, near the border with Mexico.

"The president, who visited the affected area on Wednesday, declared three days of mourning."

Prensa Libre posted video showing panic in the streets of San Marcos. They showed images of facades of buildings crumbling onto the streets, and images of doctors scrambling to help the injured.

The paper adds that through the night, the city felt 29 aftershocks that measured between 4.2 and 4.6 on the Richter Scale.

NBC reports the original earthquake was so strong that it was felt in Mexico City.

The earthquake also triggered landslides and left 76,000 without power. NBC adds:

"A Reuters witness in Guatemala City said people were evacuating homes in parts of the capital, and firefighters and rescue workers were on alert. Office workers were also evacuating buildings in Mexico City and in the capital of the Mexican state of Chiapas, across the border from Guatemala.